TORONTO — A law stripping voting rights from more than a million expatriate Canadians who have lived abroad for more than five years should be struck down as unconstitutional, according to a legal challenge served on the federal government Tuesday.

The new application, filed in Ontario Superior Court on behalf of two Canadians living in the United States, argues the five-year rule in the Canada Elections Act is arbitrary and unreasonable.

“I was very surprised to learn that I have no voting rights, that I have no capacity to interact with my government formally, that there’s no one representing me,” said Gillian Frank, 33, who works in Brooklyn, N.Y.

“My sense of being disenfranchised and the fundamental unfairness of it all motivated me (to file the suit).”

The Toronto-born Frank, who is completing post-doctoral studies in history, said he would gladly return to Canada with his Canadian wife and baby if he could find a suitable academic position.

Frank said he retains strong ties to Canada — a country that “emphasizes social justice” — and his decade-long absence has not displaced his attachment.

“I have a stake in the kind of country I want Canada to be,” said Frank, who served in the Canadian military and was a Governor-General’s Award winner.

The rule denying the vote to Canadians outside the country for more than five years was enacted in 1993 amid debate about the strength of their ties to Canada and how well informed they are about the domestic political situation.

However, it was only in 2007 that Elections Canada began to enforce the rule to “more clearly reflect the intention of Parliament,” said spokesman John Enright.

Until then, the five-year clock would reset for expats who returned even for short visits. Now, they have to “resume residency” before leaving again to regain their right to vote abroad.

Jaimie Duong, 28, of Ithaca, N.Y., said he was “shocked” to learn he couldn’t vote in last year’s federal election.

Like Frank, Duong said he is in the United States because that’s where he found work, and that he remains deeply connected to Canada.

In fact, Duong said, he follows Canadian news more closely than many of the friends he grew up with in Montreal and other parts of the country.

“No matter where I live, I will always see myself as a citizen of Canada,” he said.

According to economist Don DeVoretz, professor emeritus of Simon Fraser University, close to 10 per cent of all Canadians live abroad — a larger population than all but four of the provinces. About one-third of them live in the United States.

While some long-term expats, such as members of the Armed Forces and diplomats, are exempt from the five-year rule and can vote by way of a special ballot, DeVoretz estimates more than one million others — most of whom are Canadian born — run afoul of the law.

The charter challenge has the backing of former chief electoral officer Jean-Pierre Kingsley, who urged in 2005 the rule be scrapped — a view adopted unanimously by a parliamentary standing committee.

In an affidavit, Kingsley notes Canadian expats pay around $6 billion in income taxes to the Canadian treasury, but use significantly fewer resources than their in-country counterparts.

Toronto lawyer Shaun O’Brien — with the law firm Cavalluzzo, Hayes, Shilton, McIntyre and Cornish, which is taking the case at no charge — said expat Canadians should not have to justify why they should be able to vote.

“The government needs to justify why you shouldn’t be able to,” O’Brien said, “Having a general notion that they may not be quite as interested or quite as connected isn’t enough.”

Minister of State for Democratic Reform, Tim Uppal, called voter participation a “cornerstone” of Canadian democracy but said Tuesday it was inappropriate to comment on the case.